Self-powered devices are size-limited in part by the size of a power source used to power the device. Additionally, the shape of the power source impacts the size of the self-powered device. As such, existing power sources limit the range of shapes a self-powered device may take.
This is important in the area of implantable devices. Implantable devices, such as implantable medical devices, are increasingly able to perform new functions. However, the range of possible functions is limited by power source size and/or shape. For example, anatomical obstacles, such as the size of vessels of the circulatory system, limit the applicability of existing medical devices using known power sources. These existing medical devices are larger than preferred for implantation in some portions of the circulatory system. As such, there is a need in the art for improved flexibility in power source size and/or shape. Further, safety, patient comfort, device mass, service duration, and other factors require ongoing improvements in power sources for self-powered devices.